Molecular assembling of DNA with amphipathic peptides.
The self-assembling of double-stranded DNA with short synthetic peptides has been analysed using the fluorescent properties of the intercalating dye, ethidium bromide. Two membrane-active peptides with appropriate sequences of lysine and leucine amino acids and a short polylysine have been probed. The results revealed that the secondary structure of the peptide decisively aimed the peptide-DNA complex formation: only the longest peptide, which is the only one to exhibit an alpha-helical structure in solution, could achieve DNA compacting before charge neutralisation. The obtained complex retained a significant membrane activity as demonstrated by calcein leakage experiments. This shows that short synthetic peptides of elementary sequence can combine both membrane activity and DNA-condensing properties. The potential of these constructs as DNA carriers will be discussed.
Dufourcq
J
J
Centre de Recherche Paul Pascal, CNRS UPR 8641, Pessac, France.
Neri
W
W
Henry-Toulmé
N
N
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D004996:Ethidium; D005456:Fluorescent Dyes; D008027:Light; D008081:Liposomes; D009842:Oligopeptides / Q000737:chemistry*; D011487:Protein Conformation; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence
D005456:Fluorescent Dyes; D008081:Liposomes; D009842:Oligopeptides; D004247:DNA; D004996:Ethidium